A219115 Numbers whose squares have at least one 1 and one 2 in ternary representation.

4, 5, 7, 8, 10, 12, 13, 14, 15, 17, 20, 21, 22, 23, 24, 25, 26, 28, 30, 31, 32, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 49, 50, 51, 52, 53, 56, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 82, 84

Offset: 1

Author

Michel Marcus, Nov 12 2012

Keywords

• nonn
• base

Comments

So a(n)^2 belongs to A125293.

Complement of A176189.

Links

• K. Mahler, The representation of squares to the base 3, Acta Arith. Vol. 53, Issue 1 (1989), p. 99-106.

Crossrefs

Cf. A125293, A176189.

Programs

Mathematica

Select[Range[100],DigitCount[#^2,3,1]>0&&DigitCount[#^2,3,2]>0&] (* Harvey P. Dale, May 07 2015 *)